Wireless power transmission system and wireless power transmission method

Abstract

To provide a wireless power transmission system and a wireless power transmission method that, in an attempt to make an unmanned flight body land in a first space provided according to a route in order to feed it with power, facilitate the processing, even when the first space is unusable.SOLUTION: A wireless power transmission system includes: a first space which is provided according to a route to be flown by an unmanned flight body having a power reception part and a battery, and where the unmanned flight body can land; a first power transmission part which transmits microwaves to the power reception part of the unmanned flight body having landed in the first space; and a determination part which determines whether or not the first space can be used if a charge residual amount of the battery of the unmanned flight body is lower than a preset value, and selects the first space as a landing place for the unmanned flight body when determined that the first space can be used, whereas a second space is selected as the landing place for the unmanned flight body when determined that the first space is unusable.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a wireless power transmission system and a wireless power transmission method using microwaves. [Background technology]

[0002] Methods of supplying power to flying objects (unmanned aerial vehicles with electric rotors, multicopters) by wireless power transmission are being considered. A system has been proposed in which power is supplied wirelessly to a floating unmanned aerial vehicle from a beam source attached to a structure or a moving object (see, for example, Patent Document 1). Also, a wireless power supply system has been proposed in which a power transmission coil is installed in a station, which is a charging space fixed at a predetermined position, and a power receiving coil is attached to the unmanned aerial vehicle, thereby performing wireless power supply without contact (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2012 / 078232 [Patent Document 2] JP 2017-135880 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology disclosed in Patent Document 1 has a problem in that the unmanned aerial vehicle needs energy to remain afloat even during power supply, and is not suitable when the battery is highly charged or when the remaining charge in the battery is low.The technology disclosed in Patent Document 2 can land the unmanned aerial vehicle in a charging space to supply power, but has a problem in that it does not take into consideration how to supply power to the unmanned aerial vehicle when the charging space is unavailable.

[0005] The present invention has been made to solve the above-mentioned problems, and aims to provide a wireless power transmission system and a wireless power transmission method that can easily handle the situation when an unmanned aerial vehicle traveling a route is to land in a first space, which is a charging space provided corresponding to the route, and be powered, even if the first space is unavailable. [Means for solving the problem]

[0006] The wireless power transmission system of the present invention is provided corresponding to a route along which an unmanned aerial vehicle having a power receiving unit and a battery travels, and includes a first power transmitting unit that transmits microwaves to the power receiving unit of the unmanned aerial vehicle that has landed in a first space in which the unmanned aerial vehicle can land, and when the remaining charge of the battery falls below a preset value, determines whether the first space is available, and when it is determined that the first space is available, selects the first space as a landing location for the unmanned aerial vehicle, and when it is determined that the first space is unavailable, selects a new space in which the unmanned aerial vehicle can land and the distance from the route is greater than the distance between the route and the first space. The first power transmitting unit can transmit microwaves to the power receiving unit of the landed unmanned aerial vehicle. and a judgment unit that selects the second space as a landing location for the unmanned aerial vehicle.

[0007] The wireless power transmission method according to the present invention includes, when the remaining charge of a battery mounted on an unmanned aerial vehicle falls below a preset value, a wireless power transmission device that is provided corresponding to the route along which the unmanned aerial vehicle travels and enables the unmanned aerial vehicle to land is provided. The first power transmitting unit provided in correspondence with the route can transmit power to the power receiving unit of the landed unmanned aerial vehicle. A first step of determining whether a first space is available, and if it is determined in the first step that the first space is available, the unmanned aerial vehicle lands in the first space, and if it is determined that the first space is unavailable, the unmanned aerial vehicle is able to land and the distance from the route is longer than the distance between the route and the first space. The first power transmission unit can transmit power to the power receiving unit of the landed unmanned aerial vehicle. A second step in which the unmanned aerial vehicle lands in the second space, and in the second step, the unmanned aerial vehicle lands in the first space. , No. and a third step of transmitting power from the power transmission unit 1 to the power receiving unit of the unmanned aerial vehicle. Effect of the Invention

[0008] According to this invention, when an unmanned aerial vehicle traveling along a route is to land in a first space provided corresponding to the route in order to supply power, even if the first space is unusable, it is possible to land the unmanned aerial vehicle in a second space, which is another predetermined location, thereby achieving the effect of making it easy to handle procedures after landing in the second space. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a wireless power transmission system according to a first embodiment of the present invention. [Diagram 2] 1 is a functional block diagram showing a configuration of a wireless power transmission system in accordance with a first embodiment of the present invention. [Diagram 3] 4 is a flowchart showing the operation of the wireless power transmission system in accordance with the first embodiment of the present invention. [Figure 4] 5 is a flowchart illustrating a method of operating the wireless power transmission system in accordance with the first embodiment of the present invention. [Diagram 5] 5 is a flowchart illustrating a method of operating the wireless power transmission system in accordance with the first embodiment of the present invention. [Figure 6] 1 is a schematic diagram of a wireless power transmission system according to a second embodiment of the present invention. [Figure 7] 10 is a functional block diagram showing a configuration of a wireless power transmission system in accordance with Embodiment 2 of the present invention. FIG. [Figure 8] 10 is a flowchart illustrating a method of operating a wireless power transmission system in accordance with embodiment 2 of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals indicate the same or corresponding parts, and detailed description thereof will be omitted.

[0011] Embodiment 1 FIG. 1 is a schematic diagram of a wireless power transmission system 100 according to a first embodiment of the present invention. The wireless power transmission system 100 is a system that transmits power to an unmanned aerial vehicle 6 having a power receiving unit 7 and a battery 9. The wireless power transmission system 100 includes a first power transmitting unit 1, a first space 2, a determination unit 3, a second space 4, and an on-board device 8. The unmanned aerial vehicle 6 navigates a predetermined route mainly for the purpose of logistics and the like. The second space 4 and the on-board device 8 may be provided outside the wireless power transmission system 100.

[0012] At least one each of the first power transmission unit 1, the first space 2, and the judgment unit 3 is provided corresponding to the route along which the unmanned aerial vehicle 6 travels. The first space 2, the first power transmission unit 1, and the judgment unit 3 are provided in a structure provided along the route along which the unmanned aerial vehicle 6 travels. A structure refers to man-made objects such as steel towers and buildings, or natural objects such as trees. The first space 2 is a location where one or more unmanned aerial vehicles 6 can land. The maximum number of unmanned aerial vehicles 6 that can land simultaneously in the first space 2 is preset.

[0013] The first power transmission unit 1 transmits power to the unmanned aerial vehicle 6. More specifically, the first power transmission unit 1 transmits microwaves to a power receiving unit 7 of the unmanned aerial vehicle 6 that has landed in the first space 2. The first power transmission unit 1 is installed facing the direction of the first space 2. When multiple first power transmission units 1 are provided, a first space 2 corresponding to each of the multiple first power transmission units 1 is provided.

[0014] As shown in FIG. 1, the second space 4 is a place where the unmanned aerial vehicle 6 can land, and is provided, for example, on the ground near the route. The second space 4 is a place where the distance from the route is farther than the distance between the route and the first space 2. The second space 4 is a place where the distance from the first power transmission unit 1 is farther than the distance between the first power transmission unit 1 and the first space 2. The power receiving unit 7 of the unmanned aerial vehicle 6 that has landed in the second space 4 receives microwaves from the first power transmission unit 1. The second space 4 may also be configured to further include a power supply unit 5 as a power transmission unit that transmits power to the power receiving unit 7. The power supply unit 5 transmits power to the power receiving unit 7 of the unmanned aerial vehicle 6 that has landed in the second space 4. The power supply unit 5 transmits power to the power receiving unit 7, for example, by microwaves, electromagnetic induction, or electric field coupling. As a result of the above, the power receiving unit 7 of the unmanned aerial vehicle 6 that has landed in the second space is able to receive power from both the first power transmitting unit 1 and the power supply unit 5.

[0015] When the remaining charge of the battery 9 of the unmanned aerial vehicle 6 falls below a preset value, the judgment unit 3 selects a landing location for the unmanned aerial vehicle 6 from the first space 2 and the second space 4. Also, when there are multiple first power transmission units 1, the judgment unit 3 selects the first power transmission unit 1 that transmits power to the power receiving unit 7. The detailed configuration of the judgment unit 3 will be described later.

[0016] Here, the determination unit 3 is provided in a structure provided along the route, but may be provided in the on-board device 8. Alternatively, the determination unit 3 may be provided in both a structure provided along the route and the on-board device 8.

[0017] The following describes in more detail the configuration of the wireless power transmission system 100. Fig. 2 is a functional block diagram showing the configuration of the wireless power transmission system 100 according to the first embodiment of the present invention.

[0018] The unmanned aerial vehicle 6 is equipped with an on-board device 8. The on-board device 8 has a power receiving unit 7, a battery 9, a load 10, and a first communication antenna 11. The power receiving unit 7 receives an RF signal of microwaves 12 from the first power transmitting unit 1, and receives power by converting the RF signal into a direct current. The battery 9 can store the power received by the receiving unit. The load 10 consumes the power stored in the battery 9, and is, for example, a motor that drives the unmanned aerial vehicle 6. The first communication antenna 11 transmits power reception information from the power receiving unit 7 and information on the remaining charge of the battery 9 to the second communication antenna 14.

[0019] The first power transmission unit 1 transmits microwaves 12 to the power receiving unit 7. The first power transmission unit 1 includes a power transmission device 13, a second communication antenna 14, a control unit 15, a power source 16, a cooling unit 17, and a heat transport unit 18. The power transmission device 13 forms a beam of the microwaves 12 and radiates the beam. The second communication antenna 14 receives the power reception information of the power receiving unit 7 and the information on the remaining charge of the battery 9 from the first communication antenna 11. The control unit 15 acquires the power reception information of the power receiving unit 7 and the judgment information of the judgment unit 3, and instructs the power transmission device 13 to form a beam or switch the transmission power. The power source 16 supplies power to the power transmission device 13.

[0020] The cooling unit 17 cools the power transmitting device 13, and is, for example, a radiator or a fan. The cooling unit 17 is also provided with a heat transporting unit 18. The heat transporting unit 18 transports heat from the entire device to the cooling unit 17, and is, for example, a heat pipe or a heat exchanger. In the power transmitting device 13, amplification is performed by an amplifier or the like when converting a direct current into an RF signal. During this amplification, the power transmitting device 13 may generate heat and become hot, but since it can be cooled by the cooling unit 17, it is possible to prevent the device from breaking down.

[0021] The power transmitting device 13, the power receiving unit 7, the first communication antenna 11, and the second communication antenna 14 are each provided inside a radome 19. The radome 19 is a cover that covers the devices provided inside, and has waterproof properties and the property of transmitting radio waves.

[0022] The determination unit 3 determines whether the remaining charge of the battery 9 has fallen below a preset value. Specifically, the determination unit 3 determines whether the remaining charge of the battery 9 has fallen below a preset value based on the power reception information received from the first communication antenna 11 or the information on the remaining charge of the battery 9. Note that this determination does not require the use of information received from the first communication antenna 11. For example, if the remaining charge of the battery 9 falls below a preset value, the unmanned aerial vehicle 6 is set to perform a predetermined operation such as hovering in the air for a certain period of time. Image data of the unmanned aerial vehicle 6 is acquired by a sensor such as a camera. Then, when the determination unit 3 detects a predetermined operation of the unmanned aerial vehicle 6 using the image data acquired by the sensor such as a camera, it may determine that the remaining charge of the battery 9 has fallen below a preset value.

[0023] When the remaining charge of the battery 9 of the unmanned aerial vehicle 6 falls below a preset value, the determination unit 3 determines whether the first space 2 is available. When the determination unit 3 determines that the first space 2 is available, the determination unit 3 selects the first space 2 as a landing location for the unmanned aerial vehicle 6. When the determination unit 3 determines that the first space 2 is unavailable, the determination unit 3 selects the second space 4 as a landing location for the unmanned aerial vehicle 6. Specifically, when the number of unmanned aerial vehicles 6 landing in the first space 2 is a predetermined maximum number, the determination unit 3 determines that the first space 2 is unavailable, and when the number of unmanned aerial vehicles 6 landing in the first space 2 is less than the maximum number, the determination unit 3 determines that the first space 2 is available. In addition, even when the first space 2 is unavailable for other reasons, the determination unit 3 may determine that the first space 2 is unavailable. At this time, the determination unit 3 acquires the number of unmanned aerial vehicles 6 landing in the first space 2 by a sensor such as a camera or a contact sensor. A predetermined maximum number of unmanned aerial vehicles 6 landing in the first space 2 is registered in the judgment unit 3. After selecting the first space 2 as the landing location for the unmanned aerial vehicle 6, the judgment unit 3 issues an operational instruction to the unmanned aerial vehicle 6 to land in the first space 2. In addition, after selecting the second space 4 as the landing location for the unmanned aerial vehicle 6, the judgment unit 3 issues an operational instruction to the unmanned aerial vehicle 6 to land in the second space 4.

[0024] In addition, when it is determined that the first space 2 is unavailable, it may be determined whether or not the second space 4 is available. When it is determined that the second space 4 is available, the determination unit 3 selects the second space 4 as a landing location for the unmanned aerial vehicle 6. When it is determined that the second space 4 is unavailable, the determination unit 3 selects that the unmanned aerial vehicle 6 makes an emergency landing. Specifically, when the number of unmanned aerial vehicles 6 landing in the second space 4 is a predetermined maximum number, it determines that the second space 4 is unavailable, and when the number of unmanned aerial vehicles 6 landing in the second space 4 is smaller than the maximum number, it determines that the second space 4 is available. In addition, even when the second space 4 is unavailable for other reasons, it may be determined that the second space 4 is unavailable. At this time, the determination unit 3 acquires the number of unmanned aerial vehicles 6 landing in the second space 4 by a sensor such as a camera or a contact sensor. A predetermined maximum number of unmanned aerial vehicles 6 landing in the second space 4 is registered in the judgment unit 3. After selecting the second space 4 as the landing location for the unmanned aerial vehicle 6, the judgment unit 3 issues an operational instruction to the unmanned aerial vehicle 6 to land in the second space 4. After selecting that the unmanned aerial vehicle 6 make an emergency landing, the judgment unit 3 issues an operational instruction to the unmanned aerial vehicle 6 to make an emergency landing in a safe location.

[0025] When the determination unit 3 determines that the second space 4 is available, and there are multiple first power transmission units 1, the determination unit 3 selects a first power transmission unit 1 to transmit power from the multiple first power transmission units 1 to the power receiving unit 7 using position information of the second space, position information of the multiple first power transmission units 1, and information on whether the multiple first power transmission units 1 are available. The position information of the second space 4 is registered in advance in the determination unit 3. Furthermore, when the second space 4 is provided with a power supply unit 5, the determination unit 3 may select to transmit power from the power supply unit 5 to the power receiving unit 7.

[0026] In addition, when the judgment unit 3 determines that the second space 4 is unavailable, if there are multiple first power transmission units 1, the judgment unit 3 selects a first power transmission unit 1 to transmit power from the multiple first power transmission units 1 to the power receiving unit 7 using position information of the multiple first power transmission units 1 and information on whether the multiple first power transmission units 1 are available.

[0027] In addition, when the remaining charge of the battery 9 of the unmanned aerial vehicle 6 falls below a preset value, and there are multiple first power transmission units 1, the determination unit 3 first selects a first power transmission unit 1 to transmit power to the power receiving unit 7 from among the multiple first power transmission units 1 based on the position information of the multiple first power transmission units 1 and the position information of the current location of the unmanned aerial vehicle 6. For example, the location of the first power transmission unit 1 located closest to the current location of the unmanned aerial vehicle 6 is selected. The position information of the unmanned aerial vehicle 6 is acquired, for example, by a GPS (Global Positioning System). The position information of the first power transmission unit 1 is registered in advance in the determination unit 3. Here, it is determined whether the first space 2 corresponding to the selected first power transmission unit 1 is available for use.

[0028] A description will be given of the power transmission operation of the wireless power transmission system 100. Fig. 3 is a flowchart showing the power transmission operation of the wireless power transmission system 100 according to the first embodiment of the present invention.

[0029] When transmitting power from the power transmitting device 13 to the power receiving unit 7, in the communication start step in Fig. 3, the control unit 15 starts communication with the power receiving unit 7 before starting power transmission (step S1). Next, the state of each device in the system is monitored (step S2). Next, when starting power transmission, the power transmitting device 13 forms a beam in the direction of the power receiving unit 7 based on an instruction from the control unit 15 (step S3).

[0030] Next, the power transmitting device 13 starts transmitting microwaves 12 (calibrated microwaves) with a low output lower than the normal output (step S4). The control unit 15 obtains the power reception information from the power receiving unit 7 and checks whether there is an abnormality in the system from the received power or the microwave reception level (step S5). If it is confirmed in step 5 that there is an abnormality (if "YES"), the control unit 15 instructs the power transmitting device 13 to stop transmitting the calibrated microwaves 12 (step 8).

[0031] If it is confirmed in step 5 that there is no abnormality (if "NO"), the control unit 15 instructs the power transmitting device 13 to switch to high-power microwave power transmission, which is the normal output (step 6). The control unit 15 monitors the power reception information from the power receiving unit 7 and determines whether or not a sufficient amount of received power has been accumulated (step 7). Note that in step 7, the control unit 15 may also monitor the remaining charge of the battery 9. If it is determined in step 7 that the received power is insufficient (if "NO"), the process returns to step 6. If it is determined in step 7 that the received power is sufficient (if "YES"), the control unit 15 instructs the power transmitting device 13 to stop transmitting microwaves 12 (step 8).

[0032] 4 is a flowchart illustrating the operation method of the wireless power transmission system 100 according to the first embodiment of the present invention. Here, the trigger for entering step S9 is when the determination unit 3 determines that the remaining charge of the battery 9 has fallen below a preset value.

[0033] When the remaining charge of the battery 9 falls below a preset value while the unmanned aerial vehicle 6 is traveling along its route, the judgment unit 3 judges whether or not the first space 2 is available (step S9). If it is determined that the first space 2 is available, the unmanned aerial vehicle 6 lands in the first space 2 (step S10). If it is determined that the first space 2 is unavailable, the judgment unit 3 judges whether or not the second space 4 is available (step S11).

[0034] If it is determined in step S11 that the second space 4 is available, the unmanned aerial vehicle 6 lands in the second space 4 (step S12). If the unmanned aerial vehicle 6 lands in the second space 4 in step S12 and is equipped with a power supply unit 5, either the first power transmission unit 1 or the power supply unit 5 is selected to transmit power to the power receiving unit 7 (step S13). If it is determined that the second space 4 is unavailable, the unmanned aerial vehicle 6 makes an emergency landing in a safe location near where it is currently flying (step S14). When the unmanned aerial vehicle 6 makes an emergency landing, it is determined whether the first power transmission unit 1 is available or not (step S15).

[0035] After step S10 and step S13, the process proceeds to step S16. Also, if it is determined in step S15 that the first power transmission unit 1 is available for the power receiving unit 7, the process proceeds to step S16. In step 16, if the unmanned aerial vehicle 6 lands in the first space 2 in step 10, the process proceeds to the above step S1, and power transmission from the first power transmission unit 1 to the power receiving unit 7 is performed. Also, if the unmanned aerial vehicle 6 lands in the second space 4, and the first power transmission unit 1 is selected to transmit power to the power receiving unit 7 in step 13, the process proceeds to the above step S1, and power transmission from the first power transmission unit 1 to the power receiving unit 7 is performed. Also, if it is determined in step S15 that the first power transmission unit 1 is available for the power receiving unit 7, the process proceeds to the above step S1, and power transmission from the first power transmission unit 1 to the power receiving unit 7 is performed. When the unmanned aerial vehicle 6 lands in the second space 4, if the power supply unit 5 is selected in step S13, power transmission from the power supply unit 5 to the power receiving unit 7 is executed (step S16).

[0036] In step S8, when the control device 8 instructs the first power transmission unit 1 to stop transmitting microwaves 12, the unmanned aerial vehicle 6 returns to flight. In step 16, when power transmission from the power supply unit 5 to the power receiving unit 7 is stopped, the unmanned aerial vehicle 6 returns to flight (step S17).

[0037] 5 is a flowchart illustrating an operation method of the wireless power transmission system 100 according to the first embodiment of the present invention when the system includes a plurality of first power transmitting units 1. Here, the trigger for entering step S18 is the case where the determination unit 3 determines that the remaining charge of the battery 9 has fallen below a preset value.

[0038] When the judgment unit 3 determines that the remaining charge of the battery 9 falls below a preset value while the unmanned aerial vehicle 6 is traveling on its route, the judgment unit 3 selects a first power transmission unit 1 from the multiple first power transmission units 1 to transmit power to the power receiving unit 7 (step S18).

[0039] In the first power transmission unit 1 selected in step 18, the determination unit 3 determines whether or not the first space 2 corresponding to the selected first power transmission unit 1 is available (step S9). If it is determined that the first space 2 is available, the unmanned aerial vehicle 6 lands in the first space 2 (step S10). If it is determined that the first space 2 is unavailable, the determination unit 3 determines whether or not the second space 4 is available (step S11).

[0040] If it is determined in step S11 that the second space 4 is available, the unmanned aerial vehicle 6 lands in the second space 4 (step S12). In step S12, when the unmanned aerial vehicle 6 lands in the second space 4, a first power transmission unit 1 that transmits power from the multiple first power transmission units 1 to the power receiving unit 7 is selected. If a power supply unit 5 is provided, one of the multiple first power transmission units 1 and the power supply unit 5 that transmits power to the power receiving unit 7 is selected (step S13). If it is determined that the second space 4 is unavailable, the unmanned aerial vehicle 6 makes an emergency landing in a safe place near where it is currently flying (step S14). When the unmanned aerial vehicle 6 makes an emergency landing, it is determined whether or not there is a first power transmission unit 1 that can transmit power to the power receiving unit 7 (step S15). If it is determined in step S15 that there is a first power transmission unit 1 capable of transmitting power to the power receiving unit 7, a first power transmission unit 1 that transmits power to the power receiving unit 7 is selected from the multiple first power transmission units 1 (step S19).

[0041] If the unmanned aerial vehicle 6 lands in the first space 2 in step 10, the process proceeds to step S1 described above, and power is transmitted from the first power transmission unit 1 to the power receiving unit 7. If the unmanned aerial vehicle 6 lands in the second space 4, and the first power transmission unit 1 is selected to transmit power to the power receiving unit 7 in step 13, the process proceeds to step S1 described above, and power is transmitted from the first power transmission unit 1 to the power receiving unit 7. If the first power transmission unit 1 is selected to transmit power to the power receiving unit 7 in step S19, the process proceeds to step S1 described above, and power is transmitted from the first power transmission unit 1 to the power receiving unit 7. If the unmanned aerial vehicle 6 lands in the second space 4, and the power supply unit 5 is selected in step 13, power is transmitted from the power supply unit 5 to the power receiving unit 7 (step S16).

[0042] In step S8, when the control device 8 instructs the first power transmission unit 1 to stop transmitting microwaves 12, the unmanned aerial vehicle 6 returns to flight. In step 16, when power transmission from the power supply unit 5 to the power receiving unit 7 is stopped, the unmanned aerial vehicle 6 returns to flight (step S17).

[0043] As described above, in the wireless power transmission system and wireless power transmission method of embodiment 1 of the present invention, when an unmanned aerial vehicle 6 traveling on a route is to land in a first space 2 provided corresponding to the route and be powered, even if the first space 2 is unusable, it is possible to land the unmanned aerial vehicle in another predetermined location, the second space 4, and procedures after landing in the second space are easy.

[0044] For example, when an unmanned aerial vehicle 6 navigates a predetermined route mainly for the purpose of logistics, etc., an operation in which multiple unmanned aerial vehicles 6 simultaneously navigate the route is assumed. In such an operation, when an unmanned aerial vehicle 6 lands in a first space 2 and wants to supply power, the first space 2 may already be used by another unmanned aerial vehicle 6. In the wireless power transmission system and wireless power transmission method according to the first embodiment of the present invention, even in such a case, power can be supplied to the multiple unmanned aerial vehicles 6 without any delay by providing a second space 4, which is another charging location. In addition, when multiple first power transmission units 1 are provided, when an unmanned aerial vehicle 6 lands in the second space 4, a first power transmission unit 1 to be used can be selected from the multiple first power transmission units 1 according to the respective usage conditions, and power can be efficiently transmitted to the multiple unmanned aerial vehicles 6.

[0045] Embodiment 2 6 is an explanatory diagram illustrating a wireless power transmission system 200 according to a second embodiment. The wireless power transmission system 200 differs from the above-described embodiment in that it includes a second power transmitting unit 20. Other configurations are substantially similar. Hereinafter, configurations that are the same as or correspond to those described in the above-described embodiment are denoted by the same reference numerals, and descriptions of those configurations will not be repeated.

[0046] The second power transmission unit 20 is provided in a structure provided along the route along which the unmanned aerial vehicle 6 travels. Here, as shown in FIG. 5, it is provided in the same structure as the single first power transmission unit 1, but it may be provided in another structure. A plurality of second power transmission units 20 may be provided corresponding to the route along which the unmanned aerial vehicle 6 travels. The second power transmission unit 20 is installed facing the route, and transmits power to the unmanned aerial vehicle 6 that has taken off by microwaves. Here, the state after taking off refers to a state in which the unmanned aerial vehicle 6 is floating, such as a state in which it is moving in the air or a state in which it is hovering.

[0047] When the power receiving unit 7 receives power from the second power transmitting unit 20, the time during which the unmanned aerial vehicle 6 is interrupted and the distance it deviates from the route can be reduced compared to when the power receiving unit 7 receives power from the first power transmitting unit 1. However, since the power receiving unit 7 receives power in a taken-off state, energy is consumed to float even during power supply. Therefore, it is not suitable when the remaining charge is low and power supply is not possible in a taken-off state. Therefore, when the efficiency of power transmission is taken into consideration, the priority order for selecting the first power transmitting unit 1 and the second power transmitting unit 20 is preferably the second power transmitting unit 20, followed by the first power transmitting unit 1, in the case where power supply is possible in a taken-off state based on the remaining charge of the battery 9.

[0048] The following describes in more detail the configuration of the wireless power transmission system 200. FIG.

[0049] The wireless power transmission system 200 is configured by further providing a second power transmitting unit 20 to the wireless power transmission system 100. The second power transmitting unit 20 has a power transmitting device 13, a second communication antenna 14, a control unit 15, a power source 16, a cooling unit 17, a heat transporting unit 18, and a radome 19. Note that the second communication antenna 14, the control unit 15, the power source 16, the cooling unit 17, and the heat transporting unit 18 may be configured to be shared with the first power transmitting unit 1, if possible. FIG. 7 shows a case where the second communication antenna 14 is shared.

[0050] The following describes the configuration of the determination unit 3 that differs from the first embodiment. When the determination unit 3 determines that the remaining charge of the battery 9 has fallen below a preset value, it selects one of the second power transmission unit 20 and the first power transmission unit 1 to transmit power to the power receiving unit 7 before determining whether the first space 2 is available. Specifically, it determines whether power can be transmitted to the power receiving unit 7 of the unmanned aerial vehicle 6 that has taken off based on the remaining charge of the battery 9. When it is determined that power can be transmitted to the power receiving unit 7 of the unmanned aerial vehicle 6 that has taken off, it selects the second power transmission unit 20 as the power transmission unit that transmits power to the power receiving unit 7, and issues an operation instruction to the unmanned aerial vehicle 6 to move within a range where the microwaves transmitted by the second power transmission unit 20 can be received. When it is determined that power cannot be transmitted to the power receiving unit 7 of the unmanned aerial vehicle 6 that has taken off, it selects the first power transmission unit 1. Then, when the determination unit 3 selects the first power transmission unit 1, the determination unit 3 determines whether or not the first space 2 is available for use.

[0051] Fig. 8 is a flowchart illustrating a method of operating the wireless power transmission system 200. Fig. 8 shows a case where a plurality of first power transmitting units 1 are provided and one second power transmitting unit 20 is provided. Here, the trigger for entering step S20 is a case where the determination unit 3 determines that the remaining charge of the battery 9 has fallen below a preset value.

[0052] When the remaining charge of the battery 9 falls below a preset value while the unmanned aerial vehicle 6 is traveling along its route, the determination unit 3 selects either the second power transmission unit 20 or the first power transmission unit 1 (step S20).

[0053] If the second power transmission unit 20 is selected in step S20, the unmanned air vehicle 6 moves into a range in which it can receive microwaves transmitted by the second power transmission unit 20 (step S21).

[0054] When the first power transmission unit 1 is selected in step S20, the determination unit 3 selects a first power transmission unit 1 that transmits power to the power receiving unit 7 from the multiple first power transmission units 1 (step S18).

[0055] In the first power transmission unit 1 selected in step 18, the determination unit 3 determines whether or not the first space 2 corresponding to the selected first power transmission unit 1 is available (step S9). If it is determined that the first space 2 is available, the unmanned aerial vehicle 6 lands in the first space 2 (step S10). If it is determined that the first space 2 is unavailable, the determination unit 3 determines whether or not the second space 4 is available (step S11).

[0056] If it is determined in step S11 that the second space 4 is available, the unmanned aerial vehicle 6 lands in the second space 4 (step S12). In step S12, when the unmanned aerial vehicle 6 lands in the second space 4, a first power transmission unit 1 that transmits power from the multiple first power transmission units 1 to the power receiving unit 7 is selected. If a power supply unit 5 is provided, one of the multiple first power transmission units 1 and the power supply unit 5 that transmits power to the power receiving unit 7 is selected (step S13). If it is determined that the second space 4 is unavailable, the unmanned aerial vehicle 6 makes an emergency landing in a safe place near where it is currently flying (step S14). When the unmanned aerial vehicle 6 makes an emergency landing, it is determined whether or not there is a first power transmission unit 1 that can transmit power to the power receiving unit 7 (step S15). If it is determined in step S15 that there is a first power transmission unit 1 capable of transmitting power to the power receiving unit 7, a first power transmission unit 1 that transmits power to the power receiving unit 7 is selected from the multiple first power transmission units 1 (step S19).

[0057] If the unmanned aerial vehicle 6 lands in the first space 2 in step 10, the process proceeds to step S1 described above, and power is transmitted from the first power transmission unit 1 to the power receiving unit 7. If the unmanned aerial vehicle 6 lands in the second space 4, and the first power transmission unit 1 is selected to transmit power to the power receiving unit 7 in step 13, the process proceeds to step S1 described above, and power is transmitted from the first power transmission unit 1 to the power receiving unit 7. If the first power transmission unit 1 is selected to transmit power to the power receiving unit 7 in step S19, the process proceeds to step S1 described above, and power is transmitted from the first power transmission unit 1 to the power receiving unit 7. If the unmanned aerial vehicle 6 lands in the second space 4, and the power supply unit 5 is selected in step 13, power is transmitted from the power supply unit 5 to the power receiving unit 7 (step S16).

[0058] In step S8, when the control device 8 instructs the first power transmission unit 1 to stop transmitting microwaves 12, the unmanned aerial vehicle 6 returns to flight. In step 16, when power transmission from the power supply unit 5 to the power receiving unit 7 is stopped, the unmanned aerial vehicle 6 returns to flight (step S17).

[0059] As described above, in the wireless power transmission system and wireless power transmission method of embodiment 2 of the present invention, when an unmanned aerial vehicle traveling along a route is to land in a first space provided corresponding to the route and be powered, even if the first space is unusable, it is possible to land the unmanned aerial vehicle in a second space, which is another predetermined location, and procedures after landing in the second space are easy.

[0060] For example, when an unmanned aerial vehicle 6 navigates a predetermined route mainly for the purpose of logistics, etc., an operation in which multiple unmanned aerial vehicles 6 simultaneously navigate the route is assumed. In such an operation, when an unmanned aerial vehicle 6 lands in a first space 2 and wants to supply power, the first space 2 may already be used by another unmanned aerial vehicle 6. In the wireless power transmission system and wireless power transmission method according to the second embodiment of the present invention, even in such a case, power can be supplied to the multiple unmanned aerial vehicles 6 without any delay by providing a second space 4, which is another place where charging is possible. In addition, when multiple first power transmission units 1 are provided, when an unmanned aerial vehicle 6 lands in the second space 4, a first power transmission unit 1 to be used can be selected from the multiple first power transmission units 1 according to the respective usage conditions, and power can be efficiently transmitted to the multiple unmanned aerial vehicles 6.

[0061] In addition, the first power transmission unit 1 or the second power transmission unit 20 can be selected from the first power transmission unit 1 that transmits power to the unmanned aerial vehicle 6 that has landed and the second power transmission unit 20 that transmits power to the unmanned aerial vehicle 6 that has taken off, depending on the state of the unmanned aerial vehicle 6. Therefore, an efficient power supply method can be selected even under different conditions. For example, when the battery is highly charged or the battery is low in charge, the unmanned aerial vehicle 6 can be landed and power can be transmitted from the first power transmission unit 1 to the power receiving unit 7. When the battery does not require a high charge or the battery has energy remaining to float the unmanned aerial vehicle 6, power can be transmitted from the second power transmission unit 20 to the power receiving unit 7. When power is transmitted from the second power transmission unit 20 to the power receiving unit 7, the flight interruption time and the distance that the unmanned aerial vehicle 6 deviates from the route can be reduced compared to when power is transmitted from the first power transmission unit 1 to the power receiving unit 7.

[0062] Although the wireless power transmission systems according to the first and second embodiments have been described above, it goes without saying that the wireless power transmission system may be configured by appropriately adding or deleting part or all of the configuration according to each embodiment. [Explanation of symbols]

[0063] 1 first power transmission unit, 2 first space, 3 judgment unit, 4 second space, 5 power supply unit, 6 unmanned aerial vehicle, 7 power receiving unit, 8 on-board equipment, 9 battery, 10 load, 11 first communication antenna, 12 microwave, 13 power transmission device, 14 second communication antenna 14, 15 control unit, 16 power supply, 17 cooling unit, 18 heat transport unit, 19 radome, 20 second power transmission unit, 100, 200 wireless power transmission system.

Claims

1. a first power transmission unit that is provided corresponding to a route along which an unmanned aerial vehicle having a power receiving unit and a battery travels, and transmits microwaves to the power receiving unit of the unmanned aerial vehicle that has landed in a first space in which the unmanned aerial vehicle can land; A wireless power transmission system comprising a judgment unit that, when the remaining charge of the battery falls below a predetermined value, determines whether the first space is available for use, and if it is determined that the first space is available, selects the first space as a landing location for the unmanned aerial vehicle, and if it is determined that the first space is unavailable, selects a second space as the landing location for the unmanned aerial vehicle, where the unmanned aerial vehicle can land, the distance from the route is greater than the distance between the route and the first space, and in which the first power transmitting unit can transmit microwaves to the power receiving unit of the landed unmanned aerial vehicle.

2. The wireless power transmission system according to claim 1 , wherein the power receiving unit of the unmanned aerial vehicle that has landed in the second space receives microwaves from the first power transmitting unit.

3. The first power transmitting unit is a plurality of units, The wireless power transmission system of claim 2, wherein when the determination unit selects the second space as a landing location for the unmanned aerial vehicle, it selects the first power transmission unit to transmit power from the multiple first power transmission units to the power receiving unit using location information of the second space, location information of the multiple first power transmission units, and information on whether the multiple first power transmission units are available.

4. The wireless power transmission system according to claim 1 , further comprising a power supply unit that transmits power to the power receiving unit of the unmanned aerial vehicle that has landed in the second space.

5. The wireless power transmission system according to claim 1 , wherein the first power transmitting unit is provided in a structure provided along the route.

6. The first space is set to a maximum number of the unmanned aerial vehicles that can land therein, A wireless power transmission system as described in any one of claims 1 to 5, wherein the judgment unit judges that the first space is unavailable when the number of unmanned aerial vehicles landing in the first space is the maximum number, and judges that the first space is available when the number of unmanned aerial vehicles landing in the first space is less than the maximum number.

7. a second power transmitting unit provided corresponding to the route and configured to transmit power to the power receiving unit of the unmanned aerial vehicle floating in the air by microwaves; 7. The wireless power transmission system according to claim 1, wherein the determination unit selects either the first power transmission unit or the second power transmission unit when the remaining charge of the battery falls below a preset value, and when the determination unit selects the first power transmission unit, determines whether the first space is available.

8. The wireless power transmission system of claim 7, wherein when the remaining charge of the battery falls below a predetermined value, the judgment unit determines whether or not power can be transmitted to the power receiving unit of the unmanned aerial vehicle floating in the air based on the remaining charge of the battery, and if it determines that power can be transmitted to the power receiving unit of the unmanned aerial vehicle floating in the air, selects the second power transmission unit, and if it determines that power cannot be transmitted to the power receiving unit of the unmanned aerial vehicle floating in the air, selects the first power transmission unit.

9. a first step of determining whether a first space is available, the first space being provided corresponding to the route along which the unmanned aerial vehicle is traveling, in which the unmanned aerial vehicle can land, and in which a first power transmission unit provided corresponding to the route can transmit power to a power receiving unit of the landed unmanned aerial vehicle, when the remaining charge of a battery mounted on the unmanned aerial vehicle falls below a preset value; a second step in which, if it is determined in the first step that the first space is available, the unmanned aerial vehicle lands in the first space, and, if it is determined that the first space is unavailable, the unmanned aerial vehicle lands in a second space in which the unmanned aerial vehicle can land, the distance between the route and the second space is greater than the distance between the route and the first space, and the first power transmission unit can transmit power to the power receiving unit of the landed unmanned aerial vehicle; A wireless power transmission method comprising: a third step of transmitting power from the first power transmission unit to the power receiving unit of the unmanned aerial vehicle when the unmanned aerial vehicle lands in the first space in the second step.

10. The wireless power transmission method of claim 9 , wherein the third step transmits power from the first power transmitting unit to the power receiving unit when the unmanned aerial vehicle lands in the second space in the second step.

11. The first power transmitting unit is a plurality of units, a fourth step of selecting a first power transmission unit to transmit power to the power receiving unit from the plurality of first power transmission units using, when the unmanned aerial vehicle lands in the second space in the second step, position information of the second space, position information of the plurality of first power transmission units, and information on whether the plurality of first power transmission units are available; The method according to claim 10 , wherein the third step transmits power from the first power transmitting unit selected in the fourth step to the power receiving unit.

12. The wireless power transmission method of claim 9, wherein the third step transmits power from a power supply unit provided in the second space to the power receiving unit when the unmanned aerial vehicle lands in the second space in the second step.

13. The wireless power transmission method according to claim 9 , wherein the first power transmitting unit is provided in a structure provided along the route.

14. The first space is set to a maximum number of the unmanned aerial vehicles that can land therein, A wireless power transmission method as described in any one of claims 9 to 13, wherein the first step determines that the first space is unavailable when the number of unmanned aerial vehicles landing in the first space is the maximum number, and determines that the first space is available when the number of unmanned aerial vehicles landing in the first space is less than the maximum number.

15. a fifth step of selecting one of the first power transmission unit and a second power transmission unit that is provided corresponding to the route and transmits power by microwave to the power receiving unit of the unmanned aerial vehicle floating in the air when the remaining charge of the battery falls below a preset value; and a sixth step of transmitting power from the second power transmission unit to the power receiving unit of the unmanned aerial vehicle when the second power transmission unit is selected in the fifth step, 15. The wireless power transmission method according to claim 9, wherein if the first power transmission unit is selected in the fifth step, it is determined in the first step whether the first space is available.

16. The wireless power transmission method described in claim 15, wherein the fifth step determines whether or not power can be transmitted to the power receiving unit of the unmanned aerial vehicle floating in the air based on the remaining charge of the battery, and if it is determined that power can be transmitted to the power receiving unit of the unmanned aerial vehicle floating in the air, selects the second power transmission unit, and if it is determined that power cannot be transmitted to the power receiving unit of the unmanned aerial vehicle floating in the air, selects the first power transmission unit.

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